DESCRIPTION: (provided by the applicant) Delirium is a common disorder affecting as many as 80 percent of older hospitalized patients. Despite the fact that at least 30 percent of delirious patients continue to manifest symptoms at the time of discharge from the hospital, little investigation of delirium has occurred outside of acute care settings. The health outcomes directly attributable to delirium, the utilization of health care resources, the costs of care, the effects of continued care on delirium, and the actual course of delirium remain largely W1known. A prospective, longitudinal, cohort design with 10 years of follow-up is proposed; the work described here covers the first five years of study and reflects the first 3 years of follow-up. The specific aims are to: (1) evaluate the long-term effects of delirium on selected health outcomes, specifically, functional and cognitive status, mortality, utilization of health care resources, and the costs of care; (2) document the effect of continued care (e.g., institutionalization, rehabilitation, and home care) on the severity, duration, and recurrence of delirium; and (3) describe the natural course of delirium beyond an episode of hospitalization. Elderly subjects hospitalized for greater than 48 hours will be followed during their hospitalization. Eighty-six delirious subjects and 86 randomly selected non-delirious subjects will be followed at 1 week and 1, 2, 3, 6, 9, 12, 18, 24, 30, and 36 months after discharge. Major variables include cognition (Mini-Mental State Exam. Digit Span, modified Blessed Dementia Rating Scale), delirium (Confusion Assessment Method, NEECHAM Confusion Scale. Delirium Rating Scale), physical functional status (Activities of Daily Living, Instrumental Activities of Daily Living), resource utilization (Resource Utilization Inventory, continuing care, Readmission Inventory), and covariates (Charlson Index of Co-morbidity, Geriatric Depression Scale-Short Form). Data will be analyzed using descriptive statistics, repeated measures ANOV A and MANOV A, and survival analysis. Results of this study will establish a better understanding of the natural history of delirium, its long-term consequences, and the effects of continued care on delirium by which to design efficacious and cost-effective interventions to prevent or treat delirium.